Procalcitonin (PCT) is known to be a marker for bacterial infection and sepsis. High blood or serum levels of this peptide prohormone are indicators for severe infections.
In a clinical setting, patients with primary non-infectious diseases often are, as a precautionary measure, treated with antibiotics in order to prevent or treat potential infections which may or may not yet be manifested, independently of whether the presence of a bacterial infection has actually been diagnosed.
The present invention is based on the surprising finding of the inventors that the treatment of patients suffering from a primary non-infectious disease with an antibiotic in order to treat or prevent potential bacterial infections is in a particular group of patients associated with an increased risk of an adverse outcome. Particularly patients having a low blood PCT level are subject to an increased risk when subjected to antibiotics. It is according to the invention advisable to determine the PCT level in a sample of a bodily fluid from a patient suffering from a primary non-infectious disease before starting a potentially harmful antibiotic therapy. High blood or serum PCT levels indicate the presence of a severe bacterial infection or even sepsis and requires the treatment of the respective patient with antibiotics. However, patients suffering from a primary non-infectious disease are up to now not routinely screened for low PCT levels before starting an antibiotics therapy.